The invention relates to an x-ray diagnostic generator comprising an x-ray tube, a high voltage transformer feeding the x-ray tube, an inverter connected to the input of the high voltage transformer, and a power rectifier feeding the inverter.
In the case of an x-ray diagnostic generator of this type, it is possible to select the feed frequency of the x-ray tube high voltage transformer in the kHz-range; i.e., substantially higher than the mains frequency. On account of this feed frequency, the high voltage transformer can be provided with a substantially smaller and more lightweight construction than in the case of an x-ray diagnostic generator which is operated with the mains frequency. In an x-ray diagnostic generator of this type, the loading of the inverter is not constant; on the contrary, it is dependent upon the selected values for the x-ray tube current and the x-ray tube voltage. In the case of high x-ray tube currents and hence also high load currents of the inverter, a low x-ray tube voltage and hence also a low inverter output voltage is thus present. Conversely, the x-ray tube current and the load current of the inverter are small in the case of high x-ray tube voltages and high inverter output voltages. The switching apparatus of the inverter must be constructed such that it is not endangered by the high load currents occurring in the case of a low voltage, on the one hand, and such that it is not endangered by high voltages occurring in the case of the low load currents, on the other hand.